Research On Multi-microgrid Scheduling For Cogeneration Of Cold,Heat And Electricity

Microgrid is the main way for distributed new energy to access the distribution network,with the promotion of energy structure reform,the number of microgrids is increasing,and the electric energy interaction between microgrid and distribution network has become more frequent,which undoubtedly increases the risk and difficulty of distribution network operation.The emergence of multi microgrid system provides an effective way to reduce the risk of microgrid and distribution network operation.Combined cooling,heating and power micro grid is becoming the main type of micro grid because it can improve the rational development and utilization of local resources.Therefore,the research of combined cooling,heating and power multi micro grid system plays a vital role in the reform and development of China’s energy structure.On the basis of introducing the structure of the microgrid and the mathematical model of the related energy supply equipment,this thesis takes the CCHP multi microgrid system composed of CCHP microgrid,CHP microgrid and CCHP microgrid as the research object,aiming at the two kinds of multi microgrid scheduling models,which only include electric energy interaction and multi energy complementarity of CCHP,on the premise of meeting the energy demand of each energy supply area,the operation constraints of energy supply equipment and the trading range of electricity between each microgrid and distribution network,and takes each sub microgrid in the multi microgrid system as the interest subject,considering all kinds of expenses incurred in the operation of the system,the multi-objective optimal scheduling model of multi microgrid system with electric energy interaction and multi energy complementary cooling,heating and power complementary is established respectively,the goal is to minimize the operation cost of CCHP microgrid,CHP microgrid and CCP microgrid,and the total power fluctuation of the interconnection line between the multi microgrid system and the distribution network,.Based on the established optimal scheduling model,in order to realize the effective coordination of multiple microgrids,the operation mechanism of the combined cooling,heating and power system based on the adjustment of the deviation of cooling,heating and power is proposed.Based on the in-depth analysis of the corresponding relationship and transmission path of cold energy,heat energy and electric energy in the CCP microgrid,CHP microgrid and CCHP microgrid,for ensuring the priority utilization of the interaction between new energy and interaction between Microgrid,as well as preventing micro grid unreasonable trading electricity and effective distribution network transaction,the operation mechanism of multi microgrid system is formulated respectively according to the operation mechanism of adjusting cold,heat and electric balance by cold and thermal deviation,the interaction between micro grids and the regulation mechanism of purchasing and selling electricity of distribution network,and the operation mechanism of adjusting cold,heat and electric balance by electric deviation.In the multi energy complementary microgrid,the influence of the valley price period on the electricity sale between the microgrid and the distribution network is further considered,and the adjustment mechanism of the interaction volume between the microgrids and the electricity purchase and sale between the microgrid and the distribution network is improved.According to the designed operation mechanism,NSGA-II and improved nsag-ii algorithms are used to solve the scheduling model of combined cooling,heating and power multi microgrid system with electric energy interaction and multi energy complementarity.Using the same example background,the scheduling results of the two optimal scheduling models are analyzed.It is shown that increasing the interaction of cold and heat energy between microgrids can reduce the operation cost of each sub microgrid in the system and improve the energy utilization rate,reduce the total power fluctuation of the interconnection line between the multi microgrid system and the distribution network,and improve the economy and stability of the operation of the combined cooling,heating and power multi microgrid.